The present invention relates generally to ambulatory devices for individuals who have lost the use of their legs. More particularly, the invention relates to the design and construction of a prone stander having a mobile frame and an inclinable body support which allows the user to move between a vertical or standing position and a forwardly inclined position.
Numerous devices have been developed over the years to enable persons who have lost use of their legs to obtain some degree of mobility. The most familiar device, of course, is the wheelchair where the user, in a sitting position, is able to move by manually rotating a pair of large drive wheels on either side of the seat frame.
Although vastly successful, wheelchairs alone are not able to provide for all needs of the immobilized individual. In many instances, an immobilized person will desire to move about in a generally standing position, which is not possible with most wheelchairs. Additionally, it is frequently desirable to have the ability to lean or incline forward, a capability provided by few, if any, wheelchairs.
To provide these additional capabilities, devices referred to as mobile prone standers have been developed. Generally, these devices comprise a mobile frame having a pair of large drive wheels similar to those seen on conventional wheelchairs. Rather than having a seat for the user, however, the mobile prone stander will include an inclinable body support frame or platform where the user is strapped in a standing position facing the body support frame. The body support frame is able to incline about an axis located relatively near the axis of the main drive wheels so that the user is able to reach the main drive wheels regardless of the position of the support frame. Thus, the user is able to move about while in the standing or any other position. Such mobile prone standers are particularly useful for developmentally disabled children who benefit from an increased ability to explore their surroundings which is unavailable with conventional wheelchairs.
Previous designs for mobile prone standers, however, have suffered from certain disadvantages. In particular, the ability to adjust the size and positioning of the body support frame in order to accommodate different sizes of users has been quite limited. Although the body frames provided are generally extendable, the ability to adjust the position of the axis of inclination has generally been quite limited. Moreover, the designs have generally not been suited to the use of motorized drive means for raising and lowering the body support frames.
For these reasons, it would be desirable to provide a mobile prone stander having a body support platform where the axis of inclination is adjustable over a wide range of heights, usually being at least about 6 inches, preferably being 12 inches or greater. It would also be desirable if the design provided for a motor driven mechanism for raising and lowering the body platform which would be able to accommodate the mechanism for adjusting the height of the axis of inclination of the body support platform.
2. Description of the Background Art
U.S. Pat. No. 4,744,578 describes a mobile prone stander having a body platform which inclines about an axis fixed relative to the mobile frame. While the length of the body platform is adjustable, there is no mechanism provided to adjust the ground clearance to accommodate the increase in its length. U.S Pat. No. 4,620,714 describes a mobile prone stander which is similar to the previously-described design in many respects, except that the position of the body support platform may be horizontally and vertically adjusted by positioning serrated plates 29 and 30 which are attached to the mobile frame. The degree of vertical adjustment, however, is very limited and the mechanical stability of the attachment appears inadequate. Moreover, the design is not amenable to motorized drive of the body platform. If such a drive were mounted on the mobile frame, it would be very difficult to provide a drive linkage which could accommodate the change of body platform position. The following U.S. patents are of interest as disclosing devices for assisting disabled persons in standing and moving while in a standing position: U.S. Pat. Nos. 4,333,681; 4,155,416; 4,054,319; 4,029,089; 3,629,880; 3,493,245; 3,165,314; 3,107,105; and 3,042,131.